Level regulator for viscous liquids



NOV. 20, 1934. w THOMAS 1,981,530

LEVEL REGULATOR FOR VISGOUS LIQUIDS Filed Oct. 51, 1932 lllllllllll flaw? Way/M ra ffi wzw Patented Nov. 20, 1934 UNITED STATES,

PATENT OFFICE LEVEL REGULATOR FOR VISCOUS LIQUIDS William Thomas, Bogota, N. J., assignor to Pneumercator Company, New York, N. Y., a

corporation of Maine The present invention relates to means for maintaining liquid at approximately a given height, in a container from which the liquid is drawn continuously or intermittently for use,

by automatically delivering liquid from a source of supply in quantities equal to the withdrawals. It is particularly intended for service with liquids of high viscosity; and the embodiment of the invention here illustrated has been developed to solve the special problem of maintaining a substantially uniform level of printers ink in the fount of a printing press, from which ink is taken constantly while the press is in operation and applied by rollers to the printing types or plates of the press.

In its main features the apparatus made in accordance with the invention comprises an electric circuit making and breaking device subjected to the head of liquid in the fount or other container in which it is desired to maintain a constant-height of liquid, and a valve or its equivalent operated in consequence of the making and breaking of such circuit to cause increased flow of liquid from a main supply to '25 such container, or reduction of the flow, as required.

In the case of printers ink in an open fount, the problem is complicated by the fact that if the apparatus stands idle for a considerable length of time, as happens when, for instance, the printing press to which the fount belongs is shutdown for a number of days, or even for several hours, the ink seems to thicken or, in a manner of speaking, to'congeal, in such a manner and to such an extent that it no longer reliably transmits the pressure head in the fount to the make and break device. It becomes so sluggish, sometimes even to the point of being practically immovable in the connection from the fount to the make and break device, that the liquid head in the former fails to influence the latter in time to maintain the level within tolerable limits of variation. One feature of my invention therefore comprises special means for overcoming this condition of stagnation and avoiding its ill efiects. The invention further comprises certain refinements in the circuit making and breaking apparatus and in combinations thereof with auxiliary electrical equipment. These characteristics will now be explained in connection with the description of a specific embodiment and with reference to the drawing, in which,

Fig. 1 is a diagram showing the entire apparatus embodying the invention in combination with an ink fount and a supply of ink;

Fig. 2 is a detail sectional view of the electric circuit closer which is controlled by the head of liquid in the fount;

Fig. 3 is an elevation showing a type of solenoid operated valve suitable for controlling the delivery of ink from the main supply to the fount;

Like reference characters designate the same parts wherever they occur in all the figures.

In this specification the references to printer's ink as the liquid to be controlled, and the ink fount of a printing press as the container in which the liquid level is maintained constant, must not be construed as limiting the scope of my protection to less than the true novelty of the invention. On the contrary, I claim protection for all substantial equivalents of the specific apparatus and combination here shown, for all uses and purposes to which the apparatus and equivalent means are adapted.

Now describing the specific apparatus illustrated, part 10 represents conventionally the ink fount of a printing press in which it is desired to maintain a quantity of ink at a given level. I have not deemed it necessary to illustrate a printing press herein or the transfer means for conveying ink from the fount to the printing plates or types, for such may be of any standard or other character and are not affected at all by my invention except in so far as the maintenance of a constant level of ink in the fount improves the printing performance of the press. In a more generic sense, the fount l0 typifies a container or recipient of any sort in which a substantially uniform depth of liquid is to be maintained While withdrawals are taking place.

The part 11 represents a supply container which may be a tank in which a large quantity of ink is contained under a gravity head, or a pneumatic pressure head, superior to the head in the fount 10. It may also typify a tank or well from which liquid is taken and forwarded by a pump or the like. 12 is a valve in the pipe line 13 leading from the supply source 11 to the fount l0, and typifies generically any controller which governs the flow from the former to the latter, whether it does so directly by enlarging or restricting a flow passage in a pipe, or indirectly by governing a pump. Thus the valve 12 may typify in a broad sense the throttle valve of a steam pump or the like, the control switch of a pump-driving electric motor, etc. The specific valve here shown is operated by a solenoid 14 and its core 15, acting through levers l6 and 17 (pivoted at 13 and 19 respectively) on the stem 26 of the valve so as to open the valve when the solenoid is energized by closing of its circuit. Gravity, or a spring (not shown), or both, cause the solenoid core to descend and the valve to be closed when the solenoid circuit is opened.

A regulator 21 which embodies the make-andbreak device, or circuit closer previously referred to, is connected with the iount 10 by a pipe 22, and is located below the prescribed liquid level in the fount, as is also the connecting pipe, so as to be influenced by the head of ink in the fount. This regulator consists of a casing having an interior chamber 23, into the upper part of which the connecting pipe 22 leads by means of an elbow fitting 24 mounted in the detachable cover plate 25 of the casing. The base of the casing includes a ledge 26 at one side or" the lower part of chamber 23, between which and a projecting lug of the cover is clamped a tube 27; one end of such tube being engaged and centered by a yieldable washer 28 fitting a socket in the upper side of ledge 26, and the other end by a similar washer 29 carried by a tubular clamp screw 30 threaded through the cover projection and secured in adjusted position by a lock nut 31. A passage 32 leads from the bottom of the chamber 23 to the socket in which Washer 28 is set, and thence to the interior of thetube 27. A body of mercury 33 occupies the bottom of chamber 23, the passage 32, and the lower part of tube 27, the part 34 of such body which resides in tube 27 being one contact terminal of an electric circuit closer or switch, the other terminal of which is a contact piece 35 carried by a screw 36 which is threaded through a bushing 3'? of insulating material fixed in the upper end of screw 30, and extends thence into tube 27. This screw is adjustable through a considerable distance to vary the level at which contact is made between the terminals 34 and 35 and consequently the level or head of liquid in the fount 10. Suificient venting space is provided between the washer 29 and screw 36, and between bushing 37 and screw 30, to prevent interference by vacuum or pressure with the free rise and descent or" mercury in the tube.

One conductor 33 of an electric circuit is connected to screw 36 between nuts 39 thereon (one of which serves also as a lock nut to secure the adjustments of the screw), and another conductor 40 of the same circuit is connected by nuts 41 with a screw 42 set into the side of the chamber 23 and in electrical connection with the body of mercury 33.

It is desirable that the tube 27 be transparent so that the height of contact 35 may be easily observed, and desirable also that it be of insulating material, wherefore I prefer to make it of glass. However, it may be made of other material without departing from the invention. The contact 35 and screw 36 are necessarily of electrically conducting material, and I have found by experiment that the most durable and otherwise satisfactory materials for these members are stainless steel for the screw and a small piece of tungsten with a sharp pointed end for the contact member 35.

The regulator 21 controls the solenoid 14 through a relay device, preferably one of a character which allows only a minute current to pass between the contacts 34 and 35. I have adopted and applied to use in this connection an appliance commercially known as a micro relay which is the product of the C. F. Burgess Laboratories and is obtainable in the open market. Its essential principles are shown in the diagram of Fig. 1. It is sufficiently described for the present explanation by pointing out that electric current from the service line a-b is applied in its full strength to energize the solenoid, under control of the relay switch 43; that the contacts of the make-and-break device are connected through the conductors 33 and 40 with the grid circuit of a vacuum tube 44; that the plate circuit of such vacuum tube is connected with the coil 45 of relay switch 43; and that the relay switch contacts are normally closed. When the grid circuit is closed by contacts 34 and 35; the potential of the grid element in the vacuum tube is increased, causing current to flow through the coil 45 and opening the relay switch contacts, wherebythe solenoid of the valve 12 is deener- 'ized and the valve closed. Opening of the grid circuit by subsidence of the mercury contact 34, due to lowering of the ink level in the fount, causes opening of the valve and delivery of ink to the fount, by closing of the relay switch contact with cessation of current flow from the plate element of the tube through coil 45. These effects occur only when the line conductors a and I) are alive; wherefore if the current supply fails for any reason, the main valve automatically closes, or remains closed, and danger of overfilling the fount is avoided. a

The relay allows only a minute current to pass between the contacts 34 and 35 which reduces oxidation and disintegration to a minimum and conduces to long life of the contact 35.

A branch connection is made from the pipe 13 at the delivery side of the control valve to the connection 22, by means of a pipe 46 connected by a nipple 47 with the elbow fitting 24; such nipple having an orifice 48 opening into the fitting at an angle to both branches of the latter. This orifice is very small in proportion to the bore of the pipe 22 and fitting 24, and is substantially smaller than the bore of pipe 46. That is, it is so proportioned as to cause ink to flow at high velocity and with the effect of a jet into the connection between the fount and the regulator, whenever the valve 12 is opened. This jet has been found to have a highly important effect with ink when stifiened or congealed by having stood quiet for a long time. Its action is to supply ink to the chamber 23 and thereby raise the mercury contact 34 even though the ink in the balance of the connection 22 should be so sluggish or stiff as not to respond quickly, or even respond at all, to the increase of head in the fount. At the same time it agitates and dislodges the ink in the connection 22, eventually dissipating the congealed condition. A continuous flow of ink to the fount can never occur because, in so far as congealing of the ink impedes transmission of the pressure head in the fount to the mercury contact, it also causes building up of pressure in the chamber 23 by means of the jet from the shunt passage, to raise the mercury contact and close the valve. On the other hand, if them]: in the connection becomes too fluid to confine the pressure created by the jet flow in the chamber, it becomes equally effective to transmit the pressure head in the fount to the circuit closing contact.

In practice it has been found that the'apparatus is highly sensitive and accurate. As applied to a newspaper printing press running in regular production at the rate of 40,000 papers per hour and having an ink fount with a horizontal area of about ten square feet, this apparatus admits a, charge of ink to the fount for every forty papers on the average, the charge having a volume of approximately 1 cubic inches or less. That is, the apparatus responds to a variation of about one thousandth of an inch in the head of ink in the fount. These figures are not to be considered as in any wise limiting the invention, however; for, as previously intimated, I claim protection for all of its novel features as applied to containers of fluids of all kinds, whatever may be the dimensions of the containers and the limits within which the liquid level is maintained.

What I claim and desire to secure by Letters Patent is:

1. In a liquid level regulator, the combination with a liquid recipient and a conduit for conveying liquid to said recipient, of a primary pressure operated regulator, a pipe connecting said recipient and regulator and having a bend adjacent to the latter, a branch connection leading from said conduit to said pipe and opening through the convex side of said bend in a jet orifice.

2. The combination with a receptacle for liquid and a pressure source of the liquid, a pressure operated primary controller, means governed thereby for causing and intermitting delivery of the liquid from said source to the receptacle, a pipe from the receptacle to the pressure operated controller, and a jet inlet to said pipe in receiving connection with the pressure source.

3. The combination with a liquid receptacle, 0! a fluid-pressure actuated controller for governing the delivery of liquid to the receptacle, a liquid conduit between the receptacle and controller, and means for directing a jet of the liquid into said conduit simultaneously with delivery to the receptacle.

4. A level regulator for viscous liquids comprising the combination With an open fount in which such liquid is to be maintained at constant level, a supply source of such liquid and a conduit for conveying the liquid from said source to said fount, of a regulator for causing an intermitting flow through said conduit from the source, a hydraulically operated electrical make and break device in liquid transmitting connection with said fount to be controlled by variations in the head of liquid in the fount, means for operating said regulator under control of said make and break device, and means for delivering a jet of the liquid from a point in said conduit at the delivery side of said regulator to the connection between the fount and said make and break device.

5. In combination with a fount adapted to contain a viscous liquid, a supply source for such liquid, a conduit from the source to the fount and a regulator for increasing or reducing flow from the source through said conduit, of a hydraulically operated electrical make and break device, a connection to said device from the fount arranged to receive liquid from the fount, means controlled by said make and break device for operating said regulator, and a pipe leading from said conduit at the fount side of said regulator to said connection and opening into the latter by means of a jet orifice near the make and break device adapted to admit a jet of the liquid at high velocity into the connection when flow through the conduit is permitted by said regulator.

WILLIAM THOMAS. 

